Swap these lines:

scanf("%d%d", &a,&b);

printf(" please enter two numbers");

It should be:

printf(" please enter two numbers");

scanf("%d%d", &a,&b);

Make this:

else if (a < b)

this:

if (a < b)

So it will print the Max and the Min

int main()

{

int a, b;

printf(" please enter two numbers separated by a space ");

scanf("%d %d", &a,&b);

if (a > b)

printf("Max= %d\n", a);

else if (b > a)

printf("Max= %d\n", b);

if (a < b)

printf("Min= %d\n", a);

else if (b < a)

printf("Min= %d\n", b);

else

printf("error");

getchar();

return 0;

}

int main()

{

int a, b;

scanf("%d%d", &a,&b);

printf(" please enter two numbers");

{

if (a > b)

printf("Max= %d\n", a);

else if (b > a)

printf("Max= %d\n", b);

else if (a < b)

printf("Min= %d\n", a);

else if (b < a)

printf("Min= %d\n", b);

else

printf("error");

}

getchar();

return 0;

}